CVE-2026-30921CWE-749

OneUptime Synthetic Monitor RCE via exposed Playwright browser object

Critical · published March 9, 2026

CVSS v3.1
10.0
EPSS
1%
Percentile
44.5
In the wild
Unconfirmed
What it is

OneUptime is a solution for monitoring and managing online services. Prior to 10.0.20, OneUptime Synthetic Monitors allow low-privileged project users to submit custom Playwright code that is executed on the oneuptime-probe service. In the current implementation, this untrusted code is run inside Node's vm and is given live host Playwright objects such as browser and page. This creates a distinct server-side RCE primitive: the attacker does not need the classic this.constructor.constructor(...) sandbox escape. Instead, the attacker can directly use the injected Playwright browser object to reach browser.browserType().launch(...) and spawn an arbitrary executable on the probe host/container. This vulnerability is fixed in 10.0.20.

The record
Technical detail
CVSS v3.1
10.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00538 · 44.5th percentile
Weakness
CWE-749 · Exposed Dangerous Method or Function
Published
2026-03-09T22:58Z
EPSS history
Timeline
  • 09 MAR 22:58Z
    OneUptime Synthetic Monitor RCE via exposed Playwright browser object
    cvelistv5